"use client";

import { useState, useEffect } from "react";
import { useRouter, usePathname } from "next/navigation";
import { IconHeart } from "./Icons";
import { apiToggleLike } from "@/lib/api";
import { toast } from "@/lib/toast";

interface LikeButtonProps {
  postId: string;
  liked: boolean;
  likeCount: number;
  variant?: "default" | "compact" | "article";
}

export default function LikeButton({
  postId,
  liked: initialLiked,
  likeCount: initialCount,
  variant = "default",
}: LikeButtonProps) {
  const router = useRouter();
  const pathname = usePathname();
  const [liked, setLiked] = useState(initialLiked);
  const [count, setCount] = useState(initialCount);
  const [loading, setLoading] = useState(false);

  // router.refresh()（登录/登出后）服务端会重新下发 liked 态，同步到本地，
  // 避免客户端状态停留在刷新前的用户视角
  useEffect(() => {
    setLiked(initialLiked);
    setCount(initialCount);
  }, [initialLiked, initialCount]);

  const handleClick = async () => {
    if (loading) return;
    setLoading(true);
    // 乐观更新：先给反馈，失败再回滚
    const wasLiked = liked;
    setLiked(!wasLiked);
    setCount((c) => c + (wasLiked ? -1 : 1));
    try {
      const res = await apiToggleLike(postId);
      if (res.error === "未登录") {
        router.push(`/login?redirect=${encodeURIComponent(pathname)}`);
        return;
      }
      if (typeof res.liked === "boolean") {
        setLiked(res.liked);
        setCount(res.like_count ?? count);
      } else {
        throw new Error(res.error || "FAIL");
      }
    } catch {
      setLiked(wasLiked);
      setCount((c) => c + (wasLiked ? 1 : -1));
      toast("操作失败，请稍后重试");
    } finally {
      setLoading(false);
    }
  };

  const sizeCls =
    variant === "compact"
      ? "px-2.5 py-1.5 gap-1 text-[12.5px]"
      : variant === "article"
        ? "px-7 py-3 gap-2 text-[15px] min-w-[148px]"
        : "px-4 py-2 gap-1.5 text-sm";
  const iconSize = variant === "compact" ? 13 : variant === "article" ? 18 : 15;

  return (
    <button
      onClick={handleClick}
      disabled={loading}
      data-tip={liked ? "取消点赞" : "点赞"}
      aria-label={liked ? "取消点赞" : "点赞"}
      aria-pressed={liked}
      className={`j13-like inline-flex items-center justify-center tabular-nums rounded-full border disabled:opacity-50 ${liked ? "is-liked" : ""} ${sizeCls}`}
    >
      <span key={String(liked)} className={liked ? "j13-heart-pop inline-flex" : "inline-flex"}>
        <IconHeart size={iconSize} filled={liked} />
      </span>
      <span>{count}</span>
      {variant === "article" && <span>{liked ? "已赞" : "点赞"}</span>}
    </button>
  );
}